Dust-cap for tire-valves.



' H. P; KRAFT.

DUST CAP FOR TIRE VALV ES.

APPLICATION FILED MAR. )9, 19!].

Patented Nov. 6, 1917.

1 2 Zy Attorneys,

I v INVENTOR 12% inclose and nanny r. may or amenwoon, nnw mnsnr.

DUST-CAP FOR TIRE-VALVES.

' Specification of Letters Patent.

Application filed March-19, 1917. Serial No. 155,818.

To all whom it may concern: 2

Be it known that I, HENRY P. KRAFT, a citizen of the United States of America, residing in Ridgewood, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Dust- Caps for Tire-Valves, of which the follow-.-

of 1g. 4, shown as applied to a tire valve.

ing is a specification.

This invention relates to dust caps for tire valves, and aims to provide certain improvements therein. Such caps are ,used to protect the projecting portions of the ends of valve casings which extend inwardly from the wheel rim. The object of the present invention is to provide a cap for'this or similar purposes which shall be of very cheap and economical construction. In prior caps it has been customary to use a sheet metal shell and to swage inward a part of the shell to form a portion of reduced diameter, such portion being internally screw-threaded. This method has been adopted in lieuof internally threading the cap for its full length, the latter construction being objectionable in that it requires a very long threading operation, involves considerable wastage of metal, and also involves a long thread which in use must be kept clear and clean. In addition to spinning or 'swaging in a portion of the length of the cap, it has also been necessary to form a non-circular gripping face of some kind. Where it is desired to provide a cap which can be manipulated only by hand, this non-circular face has above the swaged-in portion. In caps which are provided with a wrench face (usually hexagonal) the formation of such wrench face has also involved another operation.

According to the present invention I provide a'cap having a portion. which is internally of less diameter than the body of the cap and which is at the same time of noncircular contour, thereby avoiding one of the operations and considerably cheapening the cost of the cap. In the preferred form of the invention the end of the cap is swaged to produce a hexagonal face which presents on the interior a succession of reduced diam: eters. The internal hexagonal part is then screw-threaded.

In the drawings, wherein I have shown several forms of the invention,-

Figure 1 is a cross-sectional view of a tire and rim,-showing a tire valve and dust cap in elevation.

taken the form of a knurl lying Patented Nov. 61,1917;

Fig. 2 is an "enlarged elevation, partly in diametrical section.

Fig. 3 is a cross-section on the line 3-3' Fig. 4 is an elevation of a modified form of cap.

Fig. 5 is an enlarged diametrical section Fig. 6 is a sectional view on the line 6-4; in Fig. 5.

Fig 7 isan elevation of another modification.

Fig. of Fig. 7, shown on the upper end of the tire valve.

'Fig. 9 is a top view of Fig. 8.

Fig 10 is a diametrical section of Fig. 2 taken on the line 1010 in Fig. 3.

Referring to the drawings, let A indicate the wheel felly having a metal rim Band adapted to engage a tire shoe C. D is avalve which projects inwardly through the rim to a greater or less extent depending upon the thickness of the latter, and E is a dust cap adapted to fit over such projecting end.

Referring first to the embodiment of the invention shown in Figs. 1, 2,

sufficiently large to enable it tofit somewhat loosely over the shell of the valve D, and when the flats H are formed, portions of the circular surface of the cap are forced inwardly to such extent that the distance across the cap from one fiatto the opposite is less than the external diameter of the valve shell. A tap is then run into the open mouth of the cap with the effect that a series of threads are formed which are preferably more, or less mutilated; that is to say, the main portions of the threads are located at the flats as indicated at I I in Fig 3. This results in the angles between the flats being unthreaded, or partially so, as shown at J in Fig. 3.

By this means the operation of forming a separate constricted portion for the thread is avoided with a consequent cheapening of 8 is an enlarged diametrical' sect-ion {3 and 10, it is seen that the dust capcomprlses a drawn oil the structure. Not only is this true, but it that there is less tendency to clog the tap,

will be observed that less metal is removed in forming the thread and that the tapping operation is not only rendered easier on this account, but also on account of the fact l prefer to employ a hexagonal it will be observed will sufiice, even a knurled shape or the like, so long as the device presents portlons which are bent inwardly to take the screwthread on the in- .terior, and outwardly to constitute a grasping portion on the exterior. The full advantages of the invention, attained unless a provides portions extending to at least the full diameter of the body of the cap, since point beyond a better gripping surface is thus attained. The hexagonal or other shape may indeed provide portions which extend beyond the,

exterior diameter of the body of the cap so long as portions are left which are within it so that a thread may be formed which will successfully engage the valve stem.

In the usual form of cap such as is illustrated in Figs. 1 to 3 and 10, the cap is adapted to be projects agreater or less distance from the rim so that there is no uniform point of engagement, and no standard distance which the cap screws over the valve shell. Hence it is necessary for the upper portion of the cap to be of greater diameter throughout than the external diameter of the valve shell, and also necessary to carry the thread up to the point where the constriction ceases. In Figs. 4 to 9 T have illustrated two forms of caps which are intended to screw upon the valve nipple as distinguished from the body of the valve shell. This'establishes a fixed which the cap cannot, be screwed, and if the valve cap is of sufiiciently small diameter (as illustrated in these figures), the constriction may be car- 'ried above the screwthread, as indicated in however, are not shape is adopted which, metal, an mternal thread applied to a valve shell which Figs. 4: to. 6, or it may be carried the total length of the cap portion as indicated in Figs. 7 to 9.

In Figs. 7 to 9 T have shown a constructtion in which the cap has a. depending portion badapted to inclose a portion of the body of the valve shell. This depending portion is preferably unthreaded and is preferably made of sufficient length to contact with the rim nut of the wheel. Such constructions are best adapted for use in connection with definite makes of motor cars employing a standard size of valve and hence having a substantially uniform degree of projection of the valve from the rim.

While I have shown and described several forms of the invention, it Will be understood that I do not wish to be limited thereto since various changes may be made therein without departing from the spirit of the invention.

What I claim is 1. A- dust cap or the like having a conby bending the stricted portion formed at the interior of said constricted portion, and/a non-circular grasping portion at the exterior of said constricted portion. 1

2. A dust cap or the like having a noncircular constricted portion formed by bending the metal, the interior of which is screwthreaded.

3. A dust cap or the like having a constricted portion formed by bending in a series of flats, the interior of such portion being screwthreaded- 4. A dust cap havinga constricted portion formed by a series of non-circular bent in portionswhich are interiorly threaded and intervening portions of greater diameter.

5.. A dust cap having a constricted portion formed by a series of non-circular bent-in portions which are interiorly threaded, and intervening portions of greater diameter which are unthreaded.

6. A dust cap or the like having" a noncircular constricted portion formed by bending the metal, the interior of which is screwthreaded, and having below said constricted portion a portion of largerdiameter which is unthreaded and adapted to embrace the body of the valve shell.

In witness whereof l have hereunto signed my name.

HENRY lP. KRAFT. 

